Premium
Etching for Microstructural Observation of Cemented Submicrometer‐Sized Carbides
Author(s) -
Jung SugWoo,
Kim Joosun,
Kang SukJoong L.
Publication year - 2001
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.2001.tb00765.x
Subject(s) - materials science , etching (microfabrication) , microstructure , scanning electron microscope , cobalt , dissolution , carbide , grain boundary , composite material , metallurgy , grain size , chemical engineering , layer (electronics) , engineering
When carbide grains in a metal matrix are very small (less than ∼1 μm), the microstructure is difficult to observe and characterize, because the grain interfaces cannot be distinguished easily via scanning electron microscopy (SEM) when the material is etched conventionally in a Murakami solution or in H 2 O‐diluted HCl. This difficulty can be overcome by etching in a newly developed etchant: 90H 2 O 2 –10HNO 3 (by vol%). After an etching of a WC‐Co sample that contained submicrometer‐sized grains, the individual grains were distinctly observable via SEM. During the etching, the dissolution rates of WC grains were different, depending on their crystallographic plane, which allowed the grain boundaries to be distinguished through observation via SEM. In addition, dissolution of the cobalt matrix occurred much faster than did the etching of the WC grains. The WC/Co interface also was revealed clearly under high magnification, because of minimization of the electromagnetic interaction between the cobalt and the electron beam of the SEM apparatus.